The determination of erosion rates from exposed tree roots in the piceance basin, colorado

Abstract

SUMMARYTree roots, exposed by hillslope erosion in the Piceance basin of Colorado, were inspected to determine average net erosion rates during the last four centuries. Twenty pinyon pine and juniper root sections were obtained from each of five sites in this region. The date when a root was first exposed by erosion was determined, for 83 of the sections collected, by one of three methods: 1. time of initial cambium dieback; 2. interpretation of annual ring growth pattern; and 3. the earliest occurrence of reaction wood.Analysis indicated no significant difference in erosion rates between the five study sites. However, a strong difference in erosion rates was noted between north-facing (0.56 mm/yr) and south-facing (1.18 mm/yr) slopes. No significant difference in erosion rates were found between various south-facing aspects and local steepness of slopes. Significant differences were noted between erosion rate and the length of time the root was exposed t o erosion. Rates of erosion on south-facing slopes in the pinyon-juniper community during the last four centuries are as follows:period (years ago) 0-99 100-199 200-299 300-399 erosion rate (mm/yr)

Response of <i>Pinus sylvestris</i> roots to sheet-erosion exposure: an anatomical approach

“…The method employed is based on the change in the ring-growth pattern (from concentric to eccentric) when the root is exposed. The quotient of the vertical distance between the upper part of the root and the present ground surface divided by the temporal interval of root exposure offers an estimation of the erosion rate in mm/year (LaMarche, 1963(LaMarche, , 1968Eardley and Viavant, 1967;Carrara and Carroll, 1979;McCord, 1987;Danzer, 1996;Bodoque et al, 2005;McAuliffe et al, 2006;Pelfini and Santilli, 2006;Pérez-Rodriguez et al, 2007).…”

Sheet erosion rates determined by using dendrogeomorphological analysis of exposed tree roots: Two examples from Central Spain

“…The quotient defi ned by the vertical distance between the upper part of the root and the present ground surface, and the temporal interval during which the root has been exposed, offers an estimate of the erosion rate in mm/year (LaMarche, 1963(LaMarche, , 1968Eardley and Viavant, 1967;Carrara and Carroll, 1979;McCord, 1987;Danzer, 1996).…”

Remedial action plan and site conceptual design for stabilization of the inactive uranium mill tailings sites at Rifle, Colorado. Appendix D, Final report

“…The average erosion rate in this area appears to be slowly increasing. The erosion rate of 5.8 feet per 1000 years determined for the Piceance Basin using data for the past 100 years (Carrara and Carroll, 1979) is anomalously high due to accelerated erosion caused by cattle grazing since the 1880s. The average erosion rate for the preceding 300 years is 1.1 feet per 1000 years.…”

“…Nevertheless, erosion rates calculated for similar lithologies and climates in the Piceance Basin area can be generally applied to the Estes Gulch area. Surface erosion rate studies in the Piceance Creek area, about 25 miles northwest of Estes Gulch, determined the rates over the past 400 years for south-facing slopes in a pinyon-juniper ecosystem on sandstone, siltstone, and claystone lithologies (Carrara and Carroll, 1979). These site conditions are roughly analogous to those of the Estes Gulch area.…”